膜蒸馏是一种低能耗、高效率的海水淡化技术.本文借鉴了制备压力推动膜材料的思路,采用非对称、孔结构高度连通的亲水聚醚砜膜,通过CF4等离子体表面改性,将亲水膜改性为疏水膜材料,并应用于直接接触式膜蒸馏(DCMD)过程.对膜的结构,接触角和DCMD性能进行了表征.结果显示, 改性后PES膜表面水接触角达120o.以4% NaCl水溶液为原料,膜蒸馏中水通量达44 kg/m2h(盐水温度7372.6oC,冷水侧温度15 oC),对盐的截留率达99.96100%.本实验表明,孔连通性较好的小孔径聚醚砜膜具有较好的膜蒸馏性能,可能成为具有商业用途的膜材料.

A new type of PES membrane for membrane distillation based an asymmetric hydrophilic PES membrane was prepared by surface modification via CF4 plasma treatment. The membrane morphology, hydrophobicity and performance in DCMD were characterized. The water contact angle of CF4 treated membrane was about 120o. A water flux of 44 kg/m2h (feed salt solution temperature at 7372.6oC, cold side temperature at 15 oC) and salt rejection of 99.96100% were obtained. The research work indicates that porous membranes with small pore size are promising for commercial applications.

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